mirror of
https://github.com/cc65/cc65.git
synced 2024-11-19 06:31:31 +00:00
725 lines
13 KiB
ArmAsm
725 lines
13 KiB
ArmAsm
;
|
|
; Graphics driver for the lores 64x56x2 mode on the NES
|
|
;
|
|
; Stefan Haubenthal, 2009-03-10
|
|
; Based on Maciej Witkowiak's line routine.
|
|
;
|
|
|
|
.include "zeropage.inc"
|
|
|
|
.include "tgi-kernel.inc"
|
|
.include "tgi-error.inc"
|
|
.include "nes.inc"
|
|
.include "get_tv.inc"
|
|
.import _clrscr, setcursor, putchar
|
|
.import paldata
|
|
|
|
.macpack generic
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table and constants.
|
|
|
|
.segment "JUMPTABLE"
|
|
|
|
; First part of the header is a structure that has a magic and defines the
|
|
; capabilities of the driver
|
|
|
|
.byte $74, $67, $69 ; "tgi"
|
|
.byte TGI_API_VERSION ; TGI API version number
|
|
xres: .word charsperline*2 ; Max X resolution
|
|
yres: .word 56 ; Max Y resolution
|
|
.byte 2 ; Number of drawing colors
|
|
.byte 1 ; Number of screens available
|
|
.byte 2 ; System font X size
|
|
.byte 2 ; System font Y size
|
|
.word $100 ; Aspect ratio
|
|
.byte 0 ; TGI driver flags
|
|
|
|
; Next comes the jump table. Currently all entries must be valid and may point
|
|
; to an RTS for test versions (function not implemented).
|
|
|
|
.addr INSTALL
|
|
.addr UNINSTALL
|
|
.addr INIT
|
|
.addr DONE
|
|
.addr GETERROR
|
|
.addr CONTROL
|
|
.addr CLEAR
|
|
.addr SETVIEWPAGE
|
|
.addr SETDRAWPAGE
|
|
.addr SETCOLOR
|
|
.addr SETPALETTE
|
|
.addr GETPALETTE
|
|
.addr GETDEFPALETTE
|
|
.addr SETPIXEL
|
|
.addr GETPIXEL
|
|
.addr LINE
|
|
.addr BAR
|
|
.addr TEXTSTYLE
|
|
.addr OUTTEXT
|
|
.addr 0 ; IRQ entry is unused
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Data.
|
|
|
|
; Variables mapped to the zero page segment variables. Some of these are
|
|
; used for passing parameters to the driver.
|
|
|
|
X1 = ptr1
|
|
Y1 = ptr2
|
|
X2 = ptr3
|
|
Y2 = ptr4
|
|
RADIUS = tmp1
|
|
|
|
ADDR = tmp1
|
|
TEMP = tmp3
|
|
TEMP2 = tmp4
|
|
TEMP3 = sreg
|
|
TEMP4 = sreg+1
|
|
|
|
; Line routine stuff (must be on zpage)
|
|
PB = ptr3 ; (2) LINE
|
|
UB = ptr4 ; (2) LINE
|
|
ERR = regsave ; (2) LINE
|
|
NX = regsave+2 ; (2) LINE
|
|
|
|
; Absolute variables used in the code
|
|
|
|
.bss
|
|
|
|
MEM: .res charsperline*2*56/4
|
|
MEMEND:
|
|
ERROR: .res 1 ; Error code
|
|
COLOR: .res 1 ; Current color
|
|
PALETTE: .res 2 ; The current palette
|
|
|
|
; Line routine stuff
|
|
|
|
OGora:
|
|
COUNT: .res 2
|
|
OUkos:
|
|
NY: .res 2
|
|
Y3:
|
|
DX: .res 1
|
|
DY: .res 1
|
|
AY: .res 1
|
|
|
|
; Constants and tables
|
|
|
|
.rodata
|
|
|
|
DEFPALETTE: .byte $0, $1
|
|
OFFSET: .byte 8, 4, 2, 1
|
|
; 00 00 00 00 01 01 01 01
|
|
; 00 01 10 11 00 01 10 11
|
|
CODE: .byte 32, 29, 26, 25, 28, 24+128, 31+128, 30+128
|
|
; 10 10 10 10 11 11 11 11
|
|
; 00 01 10 11 00 01 10 11
|
|
.byte 30, 31, 24, 28+128, 25+128, 26+128, 29+128, 32+128
|
|
|
|
.code
|
|
|
|
; ------------------------------------------------------------------------
|
|
; INSTALL routine. Is called after the driver is loaded into memory. May
|
|
; initialize anything that has to be done just once. Is probably empty
|
|
; most of the time.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
INSTALL:
|
|
jsr _get_tv
|
|
cmp #TV::NTSC
|
|
beq ntsc
|
|
; TODO ROM!
|
|
inc yres
|
|
inc yres
|
|
ntsc:; rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; UNINSTALL routine. Is called before the driver is removed from memory. May
|
|
; clean up anything done by INSTALL but is probably empty most of the time.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
UNINSTALL:
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; INIT: Changes an already installed device from text mode to graphics
|
|
; mode.
|
|
; Note that INIT/DONE may be called multiple times while the driver
|
|
; is loaded, while INSTALL is only called once, so any code that is needed
|
|
; to initializes variables and so on must go here. Setting palette and
|
|
; clearing the screen is not needed because this is called by the graphics
|
|
; kernel later.
|
|
; The graphics kernel will never call INIT when a graphics mode is already
|
|
; active, so there is no need to protect against that.
|
|
;
|
|
; Must set an error code: YES
|
|
;
|
|
|
|
INIT:
|
|
|
|
; Done, reset the error code
|
|
|
|
lda #TGI_ERR_OK
|
|
sta ERROR
|
|
; rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; DONE: Will be called to switch the graphics device back into text mode.
|
|
; The graphics kernel will never call DONE when no graphics mode is active,
|
|
; so there is no need to protect against that.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
DONE:
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETERROR: Return the error code in A and clear it.
|
|
|
|
GETERROR:
|
|
lda ERROR
|
|
ldx #TGI_ERR_OK
|
|
stx ERROR
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; CONTROL: Platform/driver specific entry point.
|
|
;
|
|
; Must set an error code: YES
|
|
;
|
|
|
|
CONTROL:
|
|
lda #TGI_ERR_INV_FUNC
|
|
sta ERROR
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; CLEAR: Clears the screen.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
CLEAR:
|
|
ldx #<MEM
|
|
stx TEMP
|
|
ldx #>MEM
|
|
stx TEMP+1
|
|
lda #0
|
|
tay
|
|
@L1: sta (TEMP),y
|
|
iny
|
|
bne @L1
|
|
inc TEMP+1
|
|
inx
|
|
cpx #>MEMEND
|
|
bne @L1
|
|
jmp _clrscr
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETCOLOR: Set the drawing color (in A). The new color is already checked
|
|
; to be in a valid range (0..maxcolor-1).
|
|
;
|
|
; Must set an error code: NO (will only be called if color ok)
|
|
;
|
|
|
|
SETCOLOR:
|
|
sta COLOR
|
|
; rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
|
|
; The page number is already checked to be valid by the graphics kernel.
|
|
;
|
|
; Must set an error code: NO (will only be called if page ok)
|
|
;
|
|
|
|
SETVIEWPAGE:
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
|
|
; The page number is already checked to be valid by the graphics kernel.
|
|
;
|
|
; Must set an error code: NO (will only be called if page ok)
|
|
;
|
|
|
|
SETDRAWPAGE:
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETPALETTE: Set the palette (not available with all drivers/hardware).
|
|
; A pointer to the palette is passed in ptr1. Must set an error if palettes
|
|
; are not supported
|
|
;
|
|
; Must set an error code: YES
|
|
;
|
|
|
|
SETPALETTE:
|
|
; Wait for v-blank
|
|
@wait: lda PPU_STATUS
|
|
bpl @wait
|
|
|
|
lda #$3F
|
|
sta PPU_VRAM_ADDR2
|
|
lda #$00
|
|
sta PPU_VRAM_ADDR2
|
|
|
|
ldy #0
|
|
lda (ptr1),y
|
|
sta PALETTE
|
|
tax
|
|
lda paldata,x
|
|
; sta PPU_VRAM_IO
|
|
|
|
iny
|
|
lda (ptr1),y
|
|
sta PALETTE+1
|
|
tax
|
|
lda paldata,x
|
|
sta PPU_VRAM_IO
|
|
|
|
lda #TGI_ERR_OK
|
|
sta ERROR
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
|
|
; set the palette should return the default palette here, so there's no
|
|
; way for this function to fail.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
GETPALETTE:
|
|
lda #<PALETTE
|
|
ldx #>PALETTE
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETDEFPALETTE: Return the default palette for the driver in A/X. All
|
|
; drivers should return something reasonable here, even drivers that don't
|
|
; support palettes, otherwise the caller has no way to determine the colors
|
|
; of the (not changeable) palette.
|
|
;
|
|
; Must set an error code: NO (all drivers must have a default palette)
|
|
;
|
|
|
|
GETDEFPALETTE:
|
|
lda #<DEFPALETTE
|
|
ldx #>DEFPALETTE
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
|
|
; color. The coordinates passed to this function are never outside the
|
|
; visible screen area, so there is no need for clipping inside this function.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
SETPIXEL:
|
|
ldx Y1 ; y+2<yres
|
|
inx
|
|
inx
|
|
cpx yres
|
|
bcc @L2
|
|
ldx X1 ; x+2<xres
|
|
inx
|
|
inx
|
|
cpx xres
|
|
bcc @L2
|
|
rts
|
|
@L2: lda X1
|
|
lsr
|
|
tay
|
|
lda Y1
|
|
lsr
|
|
tax
|
|
clc
|
|
jsr setcursor
|
|
jsr CALC
|
|
ldx COLOR
|
|
bne @set2
|
|
eor #%00001111
|
|
@set2: sta TEMP3
|
|
|
|
lda (TEMP),y
|
|
ldx COLOR
|
|
bne @set
|
|
and TEMP3
|
|
.byte $2c
|
|
@set: ora TEMP3
|
|
sta (TEMP),y
|
|
tax
|
|
lda CODE,x
|
|
@normal:jmp putchar
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETPIXEL: Read the color value of a pixel and return it in A/X. The
|
|
; coordinates passed to this function are never outside the visible screen
|
|
; area, so there is no need for clipping inside this function.
|
|
|
|
|
|
GETPIXEL:
|
|
jsr CALC
|
|
sta TEMP3
|
|
lda (TEMP),y
|
|
and TEMP3
|
|
beq @L1
|
|
lda #1
|
|
@L1: ldx #0
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
|
|
; X2/Y2 = ptr3/ptr4 using the current drawing color.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
LINE:
|
|
; nx = abs(x2 - x1)
|
|
lda X2
|
|
sub X1
|
|
sta NX
|
|
lda X2+1
|
|
sbc X1+1
|
|
tay
|
|
lda NX
|
|
jsr abs
|
|
sta NX
|
|
sty NX+1
|
|
; ny = abs(y2 - y1)
|
|
lda Y2
|
|
sub Y1
|
|
sta NY
|
|
lda Y2+1
|
|
sbc Y1+1
|
|
tay
|
|
lda NY
|
|
jsr abs
|
|
sta NY
|
|
sty NY+1
|
|
; if (x2>=x1)
|
|
ldx #X2
|
|
lda X1
|
|
ldy #0
|
|
jsr icmp
|
|
bcc @L0243
|
|
beq @L0243
|
|
; dx = 1;
|
|
lda #1
|
|
bne @L0244
|
|
; else
|
|
; dx = -1;
|
|
@L0243: lda #$ff
|
|
@L0244: sta DX
|
|
; if (y2>=y1)
|
|
ldx #Y2
|
|
lda Y1
|
|
ldy #0
|
|
jsr icmp
|
|
bcc @L024A
|
|
beq @L024A
|
|
; dy = 1;
|
|
lda #1
|
|
bne @L024B
|
|
; else
|
|
; dy = -1;
|
|
@L024A: lda #$ff
|
|
@L024B: sta DY
|
|
; err = ay = 0;
|
|
lda #0
|
|
sta ERR
|
|
sta ERR+1
|
|
sta AY
|
|
|
|
; if (nx<ny) {
|
|
ldx #NX
|
|
lda NY
|
|
ldy #0
|
|
jsr icmp
|
|
bcs @L0255
|
|
; nx <-> ny
|
|
lda NX
|
|
ldx NY
|
|
sta NY
|
|
stx NX
|
|
lda NX+1
|
|
ldx NY+1
|
|
sta NY+1
|
|
stx NX+1
|
|
; ay = dx
|
|
lda DX
|
|
sta AY
|
|
; dx = dy = 0;
|
|
lda #0
|
|
sta DX
|
|
sta DY
|
|
; ny = - ny;
|
|
@L0255: lda NY
|
|
ldy #0
|
|
jsr neg
|
|
sta NY
|
|
sty NY+1
|
|
; for (count=nx;count>0;--count) {
|
|
lda NX
|
|
ldx #0
|
|
sta COUNT
|
|
stx COUNT+1
|
|
@L0166: lda COUNT ; count>0
|
|
ora COUNT+1
|
|
bne @L0167
|
|
rts
|
|
; setpixel(X1,Y1)
|
|
@L0167: jsr SETPIXEL
|
|
; pb = err + ny
|
|
lda ERR
|
|
add NY
|
|
sta PB
|
|
lda ERR+1
|
|
adc NY+1
|
|
sta PB+1
|
|
tax
|
|
; ub = pb + nx
|
|
lda PB
|
|
add NX
|
|
sta UB
|
|
txa
|
|
adc NX+1
|
|
sta UB+1
|
|
; x1 = x1 + dx
|
|
ldx #0
|
|
lda DX
|
|
bpl @L027B
|
|
dex
|
|
@L027B: add X1
|
|
sta X1
|
|
txa
|
|
adc X1+1
|
|
sta X1+1
|
|
; y1 = y1 + ay
|
|
ldx #0
|
|
lda AY
|
|
bpl @L027E
|
|
dex
|
|
@L027E: add Y1
|
|
sta Y1
|
|
txa
|
|
adc Y1+1
|
|
sta Y1+1
|
|
; if (abs(pb)<abs(ub)) {
|
|
lda PB
|
|
ldy PB+1
|
|
jsr abs
|
|
sta TEMP3
|
|
sty TEMP4
|
|
lda UB
|
|
ldy UB+1
|
|
jsr abs
|
|
ldx #TEMP3
|
|
jsr icmp
|
|
bpl @L027F
|
|
; err = pb
|
|
lda PB
|
|
ldx PB+1
|
|
jmp @L0312
|
|
; } else { x1 = x1 + ay
|
|
@L027F:
|
|
ldx #0
|
|
lda AY
|
|
bpl @L0288
|
|
dex
|
|
@L0288: add X1
|
|
sta X1
|
|
txa
|
|
adc X1+1
|
|
sta X1+1
|
|
; y1 = y1 + dy
|
|
ldx #0
|
|
lda DY
|
|
bpl @L028B
|
|
dex
|
|
@L028B: add Y1
|
|
sta Y1
|
|
txa
|
|
adc Y1+1
|
|
sta Y1+1
|
|
; err = ub }
|
|
lda UB
|
|
ldx UB+1
|
|
@L0312:
|
|
sta ERR
|
|
stx ERR+1
|
|
; } (--count)
|
|
sec
|
|
lda COUNT
|
|
sbc #1
|
|
sta COUNT
|
|
bcc @L0260
|
|
jmp @L0166
|
|
@L0260: dec COUNT+1
|
|
jmp @L0166
|
|
|
|
; ------------------------------------------------------------------------
|
|
; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
|
|
; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
|
|
; Contrary to most other functions, the graphics kernel will sort and clip
|
|
; the coordinates before calling the driver, so on entry the following
|
|
; conditions are valid:
|
|
; X1 <= X2
|
|
; Y1 <= Y2
|
|
; (X1 >= 0) && (X1 < XRES)
|
|
; (X2 >= 0) && (X2 < XRES)
|
|
; (Y1 >= 0) && (Y1 < YRES)
|
|
; (Y2 >= 0) && (Y2 < YRES)
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
BAR:
|
|
inc Y2
|
|
@L1: lda X1
|
|
pha
|
|
@L2: jsr SETPIXEL
|
|
inc X1
|
|
lda X2
|
|
cmp X1
|
|
bne @L2
|
|
pla
|
|
sta X1
|
|
inc Y1
|
|
lda Y2
|
|
cmp Y1
|
|
bne @L1
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
|
|
; direction is passend in X/Y, the text direction is passed in A.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
TEXTSTYLE:
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
|
|
; current text style. The text to output is given as a zero terminated
|
|
; string with address in ptr3.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
OUTTEXT:
|
|
lda ptr1
|
|
lsr
|
|
tay
|
|
lda ptr2
|
|
lsr
|
|
tax
|
|
clc
|
|
jsr setcursor
|
|
ldy #0
|
|
@L1: lda (ptr3),y
|
|
jsr putchar
|
|
iny
|
|
cmp #$0
|
|
bne @L1
|
|
rts
|
|
|
|
;-------------
|
|
; copies of some runtime routines
|
|
|
|
abs:
|
|
; a/y := abs(a/y)
|
|
cpy #0
|
|
bpl absend
|
|
; negay
|
|
neg: eor #$ff
|
|
add #1
|
|
pha
|
|
tya
|
|
eor #$ff
|
|
adc #0
|
|
tay
|
|
pla
|
|
absend: rts
|
|
|
|
icmp:
|
|
; compare a/y to zp,x
|
|
sta TEMP ; TEMP/TEMP2 - arg2
|
|
sty TEMP2
|
|
lda $0,x
|
|
pha
|
|
lda $1,x
|
|
tay
|
|
pla
|
|
tax
|
|
tya ; x/a - arg1 (a=high)
|
|
|
|
sub TEMP2
|
|
bne @L4
|
|
cpx TEMP
|
|
beq @L3
|
|
adc #$ff
|
|
ora #$01
|
|
@L3: rts
|
|
@L4: bvc @L3
|
|
eor #$ff
|
|
ora #$01
|
|
rts
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Calculate all variables to plot the pixel at X1/Y1. If the point is out
|
|
; of range, a carry is returned and INRANGE is set to a value !0 zero. If
|
|
; the coordinates are valid, INRANGE is zero and the carry clear.
|
|
|
|
CALC: lda xres
|
|
sta TEMP
|
|
lda #0
|
|
sta TEMP+1
|
|
ldy Y1
|
|
@L1: lda TEMP
|
|
add xres
|
|
lsr
|
|
sta TEMP
|
|
lda TEMP+1
|
|
adc #0
|
|
lsr
|
|
sta TEMP+1
|
|
dey
|
|
bne @L1
|
|
lda TEMP
|
|
add X1
|
|
lsr
|
|
sta TEMP
|
|
lda TEMP+1
|
|
adc #0
|
|
lsr
|
|
sta TEMP+1
|
|
lda TEMP
|
|
add #<MEM
|
|
sta TEMP
|
|
lda TEMP+1
|
|
adc #>MEM
|
|
sta TEMP+1
|
|
|
|
lda X1
|
|
and #%00000001
|
|
sta TEMP3
|
|
lda Y1
|
|
asl
|
|
and #%00000010
|
|
ora TEMP3
|
|
tax
|
|
lda OFFSET,x
|
|
rts
|